Weft feeding mechanism



Aug. 12, 1969 Filed Jan. 15. 1968 M. c. MOSHER WEF'I FEEDING MECHANISM Z'Sheets-Sheet 1 INVENTOR MELVILLE C. MOSHER ATTORNEY Aug. 12, 1969 M. c. MOSHER 3,460,584

WEFT FEEDING MECHANISM Filed Jan. 15. 1968 2 Sheets-Sheet 2 3a 34 as 65 INVENTOR MELVILLE c. MOSHER ATTORNEY United States Patent 3,460,584 WEFT FEEDING MECHANISM Melville C. Mosher, Hopedale, Mass, assiguor to Crompton & Knowles Corporation, Worcester, Mass., a corporation of Massachusetts Filed Jan. 15, 1968, Ser. No. 697,724 Int. Cl. D0311 47/34 US. Cl. 139-122 9 Claims ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates to weft feeding mechanism for looms in which weft is drawn from a stationary weft supply and fed to a weft laying mechanism. The invention particularly relates to looms which operate at high speeds such as a narrow fabric needle loom. Looms of this type as shown for example in US. Patents 3,194,276 and 3,224,467 use a reciprocating weft inserter such as a needle to lay a loop of weft into a warp shed and to move outside of the warp during the crossing of the warps for a new shed. This condition requires intermittent utilization of weft which creates a series of problems at high speeds. One problem is that of maintaining a constant tension of the weft in the vicinity of the weft inserting member. A sudden use of weft, followed by a period of nonuse results in maximum weft tension followed by a slackening of the weft. This condition is likely to create unevenness in the fabric. A second problem is that of the uneven draw of weft from the supply source. The intermittent use of weft causes a jerking of the weft which puts a high, sudden strain on the weft. This strain is likely to cause the weft to rupture. The jerking of the weft also sets up vibrations which cause it to create large whipping motions commonly called ballooning. This makes the weft still harder to control and may cause it to become tangled on nearby structures.

There have been many attempts to solve the above problems but none have been completely satisfactory. Various intermittent positive feed devices have been developed which draw a certain amount of weft from the supply source and then release it to the weft inserter. This helps to prevent weft breakage and eliminates some of the weft slack near the inserter but does not eliminate jerking of the weft and does not create an even tension in the weft. The most successful weft feed arrangements have been those which utilize a constantly rotating feed member which draws weft from the supply source at constant rate to eliminate ballooning and jerking of the weft between it and the supply source. These devices are provided with a slack compensator, such as a spring located between the feed member and the weft inserter to take up slack filling and create an even tension in the weft. The compensator stores the Weft as it comes from the feed member and then yieldingly releases it for insertion into the fabric. Examples of this type of feed arrangement can be found in US. Patent 3,224,467.

One disadvantage in this type of feed mechanism however, is that it is very diflicult to control for evenness of 3,460,584 Patented Aug. 12, 1969 feed and tension. Although these devices eliminate the unevenness of feed of the intermittent feed devices, they lack their precision. There is a certain amount of slippage of the weft on the feed member which will vary due to many factors such as variations in the weft, humidity and slight variations in tension. Any change in feed rate would result in variations in the fabric. Tension devices placed on either side of the feed members help to control slipping but increase the pull on the weft which may cause it to break or cause a twist back-up thereby creating bunches or knots in the weft.

Summary of the invention It is therefore an object of the present invention to provide a positive feed mechanism which feeds weft to a weft inserter at a precise rate with a minimum of tension other than what is required for weaving and which will draw and feed weft smoothly, particularly at high speeds.

It is a further object of the invention to provide a feed mechanism which can be easily adjusted. to feed a desired amount of weft.

These objects are accomplished by the provision of a weft feed mechanism which includes a constantly rotating feed member having a guide roll spaced from the center of rotation. The constantly rotating aspect of the feed mechanism is consistent with the movement of other parts on the loom which are also rotary because of the very high speeds. The guide roll engages a section of the weft which extends between two stationary guides located be tween the weft inserter and supply source. Although this arrangement does not draw weft at an exact uniform rate, it does draw it at a smoothly accelerating rate which has nearly the effect of continuous draw at high speeds. The feed mechanism draws a precise amount of weft and therefore can be operated with a minimum rate of tension thus eliminating breakage and twist back-up. Although it is desirable to use a slack compensator with the present feed device, it is no longer essential. The present weft feed device can be adjusted so that the Weft drawing portion of its cycle will begin at the point where slack develops in the area of the weft inserter. Some of this slack results from an overfeeding of yarn due to the fact that the weft inserter has to go beyond the far edge of the cloth to enable a selvage to be formed. The present weft feed device will draw back all the slack from the weft inserter and then draw enough weft for the next weft insertion from the supply source. It is only necessary to create a slight tension between the feed device and the supply source so that the slack will be taken up before the weft is drawn from the supply. The present weft feed device therefore not only functions as a positive feeding device, but also as a tension control and slack take-up device.

Brief description of the drawings The invention and additional objects and advantages thereof, will be best understood from the following description when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a fragmentary plan view of a loom with the invention applied thereto;

FIGURE 2 is a view in elevation looking in the direction of arrow 2, FIGURE 1;

FIGURE 3 is a cross section of the adjustable guide roll taken on line 3-3, FIGURE 2;

FIGURE 4 illustrates a modified weft feed member; and

FIGURE 5 is a cross section on line 55, FIGURE 4 and showing an adjusting means for the guide roller.

Description of the preferred embodiments Referring particularly to FIGURES l-3, the loom to which the invention is applied is generally indicated at 10. The loom has a weft inserting member 12 which is reciprocated between full and dotted line positions to insert loops 14 of a filling 16 into a shed generally indicated at S. The loops 14 are knitted together to form a selvage S by a knitting needle 18. In order to knit the loops, the filling inserter has to extend beyond the selvage as shown in full lines in FIGURE 1.

The filling 16 extends from a supply package 20 and passes through the novel weft feed device generally indicated at 22 and a slack takeup device generally indicated at 24 before reaching the weft inserter 12. Slack takeup device 24 includes a pair of oppositely opposed guides eyes 26 and a spring 28 located between the guide eyes. The slack takeup device 24 is located between the feed device 22 and the weft inserting member 12. The spring 28 engages the filling which extends between guide eyes 26, and is effective to takeup any slack which develops during the reciprocation of weft inserter 12.

The weft feed device 22 which is located between the slack takeup device 24 and the weft package 20 includes a pair of guide members 30 fastened at 32 to a support rod 34 which is in turn fastened to a stationary part of the loom at 36. The outwardly extending ends of guide members 30 are formed into weft guiding loops or eyes 38. Weft feeding device 22 also includes a feed member which comprises a disc mounted by a set screw 41 on a. shaft 42. Disc 40 has a slot 44, see FIGURE 2, which extends outwardly from the shaft 42. A guide roll 45 having a central circumferential groove 46, see FIGURE 3, is rotatably mounted on a bushing 47. Roll 45 is held on bushing 47 by a bolt 48 which is threaded into a holding member 49. Bushing 47 has an enlarged portion 50 which together with member 49 forms a clamp against the edges 52 of the slot 44. The enlarged portion 50 also act as a spacer to hold roll 45 away from the disc. Holding member 49 has a reduced portion 53 which fits into slot 44 and allows the roll to be guided adjusted along slot 44 when bolt 48 is loosened. Shaft 42 is driven by equal pulleys 58 and a belt 60 from a lay drive shaft 62. Shaft 42 is therefore driven in timed relation to other motions on the loom and makes one revolution for each weft insertion.

During operation of the loom, the weft feeding mechanism operates as follows: The filling which extends between eyes 38 is looped around roll 45 into a loop 64. The constantly rotating disc 40 is set on shaft 42 and timed so that roll 45 reaches the upper position, as shown in full lines in FIGURE 2, as weft inserter 12 reaches the full line position as shown in FIGURE 1. As weft inserter 12 moves from the full to the dotted line position in FIGURE 1, roll 45 moves from the full line to the dotted line position in direction of arrow A, FIG- URE 2. During this motion, roll 45 draws a certain amount of filling from package 20. The amount of filling drawn from the package 20 will be equal to the difference in total filling length between the dotted and full line positions of filling loop 14 minus the portion of the full line which extends beyond the selvage S. The length of filling so drawn will be equal to a weft insertion. This amount will be released to the weft inserter as the weft inserter moves from the dotted line position to the full line position in FIGURE 1 by the motion of roll 45 from the dotted line to the full line position in FIGURE 2. The roll 45 is adjusted along slot 44 at a distance from the center of the disc which is approximately equal to one-half of the width of the fabric F being woven. Finer adjustments can be made so that the device will feed an exact amount of weft to the weft inserter 12.

As previously described, the takeup device 24 takes up the slack produced by the over-travel of the weft inserter. The takeup device could be eliminated if desired by adjusting the timing on the feed device so that roll 45 begins to draw weft earlier in the cycle. By placing a tension device between the feed device and the supply package as indicated at 65, the weft feed device will draw the slack from the weft inserter first before drawing from the supply package. Roll 45 will be adjusted from the center of shaft 42 so that the amount of yarn drawn from the full line position to the dotted line position in FIGURE 2 will equal the slack plus the amount of weft needed to lay a double pick as represented by loop 14. When the roll moves from the dotted line position to the full line position in FIGURE 2, the amount of filling given up to the weft inserter will also equal the amount of filling needed to insert a double pick plus the slack. When the weft feed device is used in this way, the only tension that is required is that produced by tension device 65 which can be very light.

Referring to FIGURES 4 and 5, there is shown a modified feed member generally indicated at 66. Feed member 66 includes an arm 68 adjustably fastened to shaft 42 by a locking screw 70. A tubular slider 72 having a rectangular cross section fits on arm 68 and is slidable thereon. A screw 74 holds slider 72 to arm 68 in the desired position and can be loosened to allow the slide to be adjusted on arm 68. A roll 76 similar to roll 45 is rotatably mounted on slider 72 by a pin 78. Arm 68 and roll 76 will be rotated by shaft 42 in the same manner as described for disc 40 and roll 45.

It should be apparent that other forms of constantly 1'0- tating feed members may be used together with other mean for adjustably mounting a feed roll thereon by those skilled in the art without departing from the spirit of the invention. The scope of the invention is more accurately defined in the following claims.

I claim:

1. A weft feeding mechanism for advancing weft from a stationary supply to weft inserting means in a loom, wherein the weft is used intermittently in a weft inserting cycle, comprising:

(a) a pair of spaced stationary weft guides located between said stationary supply and said weft laying means through which said weft extends;

(b) a constantly rotating feed member which makes one rotation for each weft laying cycle; and

(c) a feed guide attached to and protruding from one face of said feed member at a distance from the center of rotation thereof and being the only protuberance extending from said face for continuous engagement with the portion of said weft which extends between said spaced guides, whereby weft is drawn from said package during a portion of the rotation of said feed member and released to said weft inserting means during another portion of the rotation of said feed member.

2. The weft feeding mechanism as described in claim 1 wherein said feed guide comprises a roller pivotally mounted on said feed device and having a circumferential groove for engaging said weft.

3. The weft feeding mechanism as described in claim 1 wherein said feed guide is attached to said feed member by means for adjustably positioning and holding said feed guide at varying distances from the center of rotation of said feed member, whereby the amount of weft which is drawn from said supply and released to said weft inserting means can be varied.

4. The weft feeding mechanism as described in claim 3 wherein said feed member has a slot which extends away from said center of rotation and said means for adjustably positioning and holding said feed guide comprises a clamp which is guided in said slot and which supports said feed guide.

5. The weft feeding mechanism as described in claim 4 wherein said support member is a disc.

6. The weft feeding mechanism as described in claim 4 wherein said feed member is a crank arm and said means to adjustably position and hold said feed guide comprises:

(a) a sleeve slidably mounted on said crank arm and which supports said feed guide; and

(b) means for releasably locking said sleeve to said arm in any position on said arm.

7. The weft feeding mechanism as described in claim 6 wherein said sleeve has a threaded hole through one side thereof and said locking means is a screw.

8. A weft feeding and slack takeup mechanism in a loom wherein weft is drawn from a stationary supply source to a weft inserting means to be used intermittently in a weft inserting cycle, said mechanism comprising:

(a) a pair of spaced stationary yarn guides located between said stationary supply and said weft laying means;

(b) a constantly rotating feed member which makes one rotation for each weft laying cycle; and

(c) a feed guide attached to and protruding from one face of said feed member at a distance from the center of rotation thereof and being the only protuberance extending from said face for continuous engagement with a portion of said weft which extends between said spaced yarn guides, whereby slack weft is taken up and additional weft is drawn from said supply source during one portion of the rotation of said feed member and released to said weft inserting means during another portion of the rotation of said feed member. 9. The weft feeding mechanism as described in claim 8 wherein said feed guide is attached to said feed member by means for adjustably positioning and holding said feed guide at varying distances from the center of rotation of said feed member, whereby the amount of Weft drawn from said supply and released to said weft inserting means can be varied.

References Cited HENRY s. JAUDON, Primary Examiner US. 01. X.R. 

